CARACAS (AFP) — Civil servants, housewives and retirees alike lined up in Venezuela's capital Caracas on Saturday as thousands volunteered to join the country's militia in case there is a United States invasion.

President Nicolas Maduro called on citizens to respond to the current US "threat" and sign up over the weekend to the Bolivarian Militia, a civilian corps linked to the South American country's armed forces.

The show of force is also intended to send a message to Washington, which has issued a $50-million bounty for Maduro — who is accused by the Trump administration of leading a drug cartel — and has stationed three warships off Venezuela's coast for what the US says are anti-drug operations.

Militia registration centers were set up in the capital's squares, military and public buildings and even in the presidential palace Miraflores.

Volunteers could also sign up in the Mountain Barracks, which is home to the mausoleum of late socialist leader Hugo Chavez, in a densely populated area with large housing projects and crumbling brick houses.

"Have you previously served?" a militia member dressed in camouflage asked Oscar Matheus.

"I'm here to serve our country," the 66-year-old auditor told Agence France-Presse. "We don't know what might happen, but we must prepare and keep resisting."

"The homeland is calling us. Our country needs us," said 51-year-old Rosy Paravabith.